1. Field of the Invention
The present invention concerns a boot intended for gliding sports, in which the foot is connected to the gliding device by means of a boot, and more specifically, a boot adapted to surfing on the snow or "snowboarding", or also to skating, ice skating, in-line skating, or skiing (cross country skiing, telemark, etc.).
2. Discussion of Background and Material Information
The practice of this type of sport has revealed problems linked to the construction of currently existing boots, which boots do not respond to the dynamic forces induced by these sports.
Indeed, it has been established that it is necessary to guarantee a certain comfort and flexible retention of the foot, and to enable it to take various positions according to situations encountered or desired during gliding.
On the other hand, it is also necessary to guarantee rigid support for the foot and lower part of the leg of the user. The support means must be strong, especially as the gliding member (skate, snowboard) is of a more substantial size and since the glide is most often undertaken in rapid fashion and according to more or less acrobatic figures/patterns.
In these conditions, the arms of the lever resulting from the dimensions of the gliding member induce forces that are sometimes very substantial on the foot or the lower part of the leg. Thus the foot and lower part of the leg must also be firmly maintained, frontwardly or rearwardly along the support axes, as well as laterally and in torsion. These firm maintenance requirements are contrary to the notion of comfort.
Currently, the market offers boots of either a flexible, rigid, or semi-rigid construction.
The flexible boots generally ensure retention of the foot by deformation of the upper (leather, fabric, flexible plastic), by bringing the latter close to the foot using a lacing system which tends to press the foot against the sole of the shoe, or yet by an internal tightening device, pressing the foot against the sole, independently of the external upper.
Rigid or semi-rigid boots, such as those developed for the alpine ski, as well as snowboard, ice skate, or in-line skate, comprise an internal liner arranged in a plastic or rigid leather shell, enveloping the foot and lower part of the leg.
The foot is then retained firmly by means of the liner, either by the relative deformation of the shell, which holds the liner and tends to immobilize it by means of external closure members of the shell, such as hooks and/or a collar on the lower part of the leg, or by internal tightening devices of the shell which also tend to immobilize the liner with respect to the sole, while spacing it from the shell by means of cables and support elements controlled from the outside of the boot by closure and adjustment members.
Each of the known types of boots mentioned above has its own, independent advantages and disadvantages.
Indeed, if the foot and the lower part of the leg are properly linked to the sole by virtue of the tightening obtained with the help of flexible materials, which provides good transmission of information originating from the gliding member, in return, the supports are not very strong because of the flexibility of the upper, which, in addition, can prove dangerous or fatiguing for the resistance of the foot and the lower part of the leg which will have to compensate for this lack of support by more substantial forces.
On the other hand, in rigid boots there is no lack of support to suffer but, on the contrary, the foot is less well retained in the boot due to possible relative movements between the shell and the liner, and thus between the liner and the sole, barring very considerable deformation of the shell on the liner, generating highly adverse pressures on the foot, and thus, considerable discomfort.
In other words, the support necessitates the use of rigid parts or elements which are not easily compatible with a specific adaptation to the morphology of the foot, which is necessary for a comfortable retention of the foot and for good transmission of information.
It has been demonstrated, according to a first phase of the inventive step, that all the problems cannot be treated together in the same zones of the boot and that consequently, they must be treated separately. The flexible retention of the foot and the lower part of the leg must not interfere with the rigid supports in order to limit the complexity of the boot to be perfected according to these criteria, and which is the object of the present invention.